Having recently acquired a damaged A-136, I have now ended up with a damaged A-143-1. At least the Waveshaper was sold as damaged, the A-143-1 was sold as new :(

Channel's 1, 2 and 3 seem fine. Neither of the two LED's on channel 4 light up and the output's seem to do nothing. I noticed on the back of the module channel 4 is the first channel to receive power from the bus. I guess this could be a case of the module's power having been plugged in upside down. The waveshaper had the same problem and replacing the two amp's fixed it. There was visible burn markings on the solder of the waveshaper, channel 4 on the A-143-1 looks fine, I can't viably see anything wrong with it, channel 4 looks identical to 1, 2 and 3. I guess replacing the four chips (Amps ) on the PCB would be the first thing to try

Thanks for any help,
Jonathan